1. The Safety Valve Specialist
Thermostatic
Shower Controls
Combining expertise, reliability and safety in a range
of thermostatic shower controls

2. Thermostatic Shower Controls
HOT WATER BURNS LIKE FIRE
Picture © Reliance Worldwide
HOT WATER
Every year 570 people are admitted to UK Hospitals suffering from severe
and debilitating scald injuries, almost 90% of these who require hospitalisation
are children. In addition, 23 people are killed every year by being immersed
in hot water by mistake by a carer or nurse or by falling into a bath and not
being able to get out quickly enough. These are sobering statistics when you
consider that the burns suffered by scald victims are every bit as painful and
destructive as those suffered by victims of fires or explosions. While children
are generally scalded because they do not identify or understand the risk, the
elderly or disabled are more likely to be injured or in the worst case killed as
a result of not being physically able to remove themselves from the scalding
situation, when they find themselves in danger. At 60°C an adult will suffer third degree burns in less than 6 seconds, or
a child in less than 1.5 seconds. Clearly anyone who is marginally impeded in their movements is going to suffer a serious
scald injury at such high temperatures.
BURNS LIKE FIRE
Temperature versus exposure time
The severity of a burn will be affected by the temperature and the time of exposure to hot water:
Type of
Burn
Time of exposure in minutes and seconds
Temp
45°C
50°C
55°C
60°C
65°C
70°C
75°C
80°C
Adult 3rd
>60 m (e)
300 s
28 s
5.4 s
2.0 s
1.0 s
0.7 s
0.6 s (e)
Adult 2nd
>60 m (e)
165 s
15 s
2.8 s
1.0 s
0.5 s
0.36 s
0.3 s (e)
Child 3rd
50 m (e)
105 s
8s
1.5 s
0.52 s
0.27 s
0.18 s
0.1 s (e)
Child 2nd
30 m (e)
45 s
3.2 s
0.7 s
0.27 s
0.14 s
<0.1 s
<0.1 s (e)
(e) = estimated
The table has been taken from a 1993 ASSE paper. There are a number of different published figures used to indicate the effect of temperature and time on
the severity of the resultant burn. All figures used must be taken as indicators only as from the difference in published figures it is clear that the results will
vary from person to person.
The best solution to prevent scalding is to fit a thermostatic shower control: which will mix together the hot and cold
water to an accurately controlled and stable outlet temperature, typically between 38-44°C to prevent scalding the end
user. There are two schemes which are set up especially to verify that thermostatic controls are fit for purpose and will
therefore provide dependable protection from scalding. The TMV3 scheme approves controls for facilities in healthcare
premises where the users are deemed to be at a high risk of scalding. The TMV2 scheme approves controls for domestic
and general public use.
TMV3 Scheme & NHS Model Engineering Specification D08
The NHS Model Engineering Specification D08 forms the basis of the testing requirements for the TMV3 Scheme.
The D08 specification was created in 1997 and has remained largely unchanged since then. It was written together
by the UK regulators, test houses, industry and NHS Estates bodies who understand that the unique qualities found
in the UK plumbing system create challenges that are different from anywhere else in the world. The specification
has been written to cover performance at both high and low pressures and covers a multitude of other requirements.
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3. Thermostatic Shower Controls
For a manufacturer to gain TMV3 approval they must go through a difficult approval process which is carried out by Buildcert, a
third party approval organisation. Upon application for approval all relevant information is required including drawings, marketing
information, instructions, and most important, samples of the valve will be submitted for testing. Some keys tests are:
• Endurance testing of the thermal element
• Temperature response on adjustment
• Temperature stability on changing pressures and reduced flow rates
• Thermal shut off
• Temperature overshoot on start-up (hot spike testing)
As these points show, the TMV3 scheme is a comprehensive and difficult approval to meet and necessarily so, for a valve that
is really a safety valve. Once testing is completed the valve is presented to the TAP (technical assessment panel): a committee
made up of experts, who examine the information provided to make sure the product meets all the requirements of the TMV3
scheme. If and when granted, a TMV3 approval certificate is provided which is valid for a period of 5 years. The valves are
audited twice during this time, and then after 5 years the entire approval process begins again.
The TMV2 Scheme
In order for a manufacturer to achieve TMV2 approval for a control to comply with BS EN 1111 or BS EN
1287 by Buildcert so that it can be marketed as a TMV2 scheme approved product, again there is a very difficult
approval process to go through. It begins with the manufacturer submitting an approval application to Buildcert,
requesting them to test a control to the TMV2 scheme. All relevant information is supplied to Buildcert at this
time, including drawings, marketing information, instructions etc. Once Buildcert processes the application they will then ask
the company to submit samples of the valve in question for testing. As long as the valve passes all of the required performance
tests then it is submitted to the TAP (technical assessment panel): a committee of experts, who examine the information
provided to make sure the product meets all the requirements of the TMV2 scheme. If everything is accepted then the TAP
committee will advise the secretary of Buildcert to issue a certificate of approval and to list the valve on the Buildcert website.
As with the TMV3 scheme, the certificates are valid for a period of 5 years, products are audited twice during this time period,
and after 5 years the entire approval process begins again.
Building Regulations: Part G - Hot Water Safety
Part G (sanitation, hot water safety and water efficiency) of the Building
Regulations for England and Wales includes a requirement for temperature
control devices to be fitted in the bathroom of all new domestic properties and
major refurbishments which involves the movement or replacement of the bath.
This requirement to limit the temperature of hot water is currently imposed only
on the bath, as that is deemed to present the highest risk for scalding. Showers
and basins do not fall under this regulation. The temperature control device
must be capable of keeping a precise and stable temperature to a maximum
of 48°C. TMV2 approved controls are specifically designed, built and tested for
the domestic market, like our Heatguard® BSM which is shown on page 8 of
this brochure. Only controls which have been verified under the TMV2 scheme
should be used to control the hot water to the bath, as these have undertaken
third party testing to ensure they comply with the requirements of Part G.
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4. Thermostatic Shower Controls
Showerguard® E3 & C3 Sequential Control Shower
The Showerguard® E3 & C3 shower controls are TMV3 approved thermostatic sequential showers. A sequential control is
one where the on/off operation and temperature control are achieved by turning the same control knob; the first movement
turns the shower to the cold position and any subsequent movement counter clockwise increases the temperature up to a
set maximum (pre-set 38°C). They are built around a single cartridge principle, meaning that the main working components
are included in an easy to replace one-piece cartridge. Each shower includes integral check valves and strainers. The
Showerguard® C3 also incorporates built-in isolators. Both inlet and outlet connections can be altered on site for complete
flexibility of installation, to suit the orientation of the supply pipes. In addition to this the outlet fitting can be removed and
reversed so that top or bottom connections can be used.
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Rapid failsafe on both hot and cold supply failure
Provides stable mixed water temperature
Lever handle for ease of use
Rotational elbows through 360° to suit any pipework orientation
Top or bottom outlets can be changed on site for flexibility
Single piece thermostatic cartridge, same for both E3 and C3 models
Includes check valve, strainer and flow regulator (plus isolators on C3 model)
Product Range
SHOW 153 100 - Showerguard® E3 Exposed Sequential Shower
SHOW 153 150 - Showerguard® C3 Concealed Sequential Shower
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5. Thermostatic Shower Controls
Materials
Dimensions
Body Brass
Showerguard® E3
199
Seals EPDM - viton
150 CTRS
Strainer Stainless steel
Cartridge Body
Noryl & Ultem
Spring Stainless steel
Piston Noryl
Specifications
Hot temperature supply range
50-85°C
Recommended hot supply temperature
55-60°C
Cold temperature supply range
5-25°C
Maximum static pressure
10bar
Maximum working pressure
5bar
Minimum working pressure
1bar
Supply pressure variation ratio
5:1
Factory set temperature
38°C +/-2°C
Minimum temperature differential
(Hot inlet to mixed outlet)
10°C
Regulated flow rate
8l/min
Connection size
Inlet 15mm
Outlet ½” MBSP or 15 mm
130
45
Ø 60
Ø 49
Ø 70
43
Standards
Showerguard® C3
Complies with BS 7942
255
NHS MES D08
Approvals
WRAS
205
TMV3 approved
Flowrate Graph
166
6.0
82
51
Pressure (bar)
5.0
4.0
3.0
2.0
1.0
0
0
5
10
15
20
25
30
35
All dimensions in mm unless
otherwise stated
40
Flow (l/min)
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5

6. Thermostatic Shower Controls
Heatguard® DC153 & CS3 Shower Control
The Heatguard® DC153 & CS3 are TMV3 approved shower valves of contemporary style with unique easy to use separate
controls for both flow and temperature, which allow accurate temperature selection. These showers are specially designed
with a large internal flow path which gives a greater flow at low pressure. The Heatguard® DC153 incorporates pushfit
connections on the inlet and a choice of either top or bottom outlet for freedom of design and installation, the outlet fitting
can be removed and reversed so that either a compression or flat faced fitting can be used. Both the Heatguard® DC153 &
CS3 come complete with serviceable strainers and a one-piece thermostatic cartridge, to ensure quick and easy servicing.
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TMV3 approved for safe use in installations where the user is deemed to be at high risk
Single piece thermostatic cartridge, means simple maintenance
Pushfit connections for ease of installation (DC153 version only)
Top or bottom outlets can be changed on site for flexibility
Rotational elbows through 360° to suit any pipework orientation (DC153 version only)
120° ceramic disc flow control for easy operation
Product Range
THRM 153 011 – Heatguard® DC153, exposed, chrome
THRM 153 021 – Heatguard® DC153, exposed, chrome, c/w lever handles
THRM 503 001 – Heatguard® CS3, concealed, chrome
THRM 503 010 - Heatguard® CS3, concealed, chrome, c/w lever handles
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7. Thermostatic Shower Controls
Materials
Standards
Body Cast brass
Complies with BS 7942
Strainer Stainless steel NHS MES D08
Cartridge Brass
Seals NBR
Approvals
Finish Chrome
WRAS
TMV3 approved
Specifications
Maximum hot temperature supply
85°C
Recommended hot supply temperature
55-60°C
Cold temperature supply range
5-25°C
Maximum static pressure
10bar
Maximum working pressure
5bar
Minimum working pressure
0.2bar
Supply pressure variation ratio
10:1
Factory set temperature
38°C +/-2
Flowrate Graph
80
70
Flow (L/M)
60
50
40
30
20
10
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
2
3
4
5
6
Pressure (bar)
Minimum temperature differential
(hot inlet to mixed outlet) 10°C
Regulated flow rate
8l/min
Dimensions
Heatguard® DC153
130
Heatguard® CS3
50 MIN
70 MAX
33
87
70
130
148
37
70
52
185
153
132
28
150
48
190
G3/4”
ALL PORTS
All dimensions in mm
unless otherwise stated
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7

8. Thermostatic Shower Controls
Heatguard® BSM Bath Shower Mixer
The Heatguard® BSM is a dual control TMV2 approved thermostatic bath shower mixer. It is built around a two
cartridge principle, meaning that all the working thermostatic components are included in an easy to replace onepiece thermostatic cartridge and the flow control is contained within another cartridge. Check valves and strainers are
included within the design of the shower. A high temperature override button ensures the user has total control over
the temperature safety. The deck mounted version includes isolating valves which are accessible from above the bath,
this makes any maintenance easier and eliminates the need for access points or removal of the bath panel.
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Rapid failsafe on both hot and cold supply failure
Provides stable mixed water temperature
Includes check valve, strainer and flow regulator
Part G compliant
Diverter between bath and shower integral in flow control
Both deck and wall mounted versions available
Deck mounted version comes with isolators accessible from above the bath
Product Range
THRM 700 001 – Heatguard® BSM Bath Shower Mixer – Deck mounted
THRM 700 050 - Heatguard® BSM Bath Shower Mixer – Wall mounted
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9. Thermostatic Shower Controls
Materials
Standards
Body Brass
Complies with BS EN 1111
Seals EPDM
Strainer Stainless steel
Cartridge body Udel
Approvals
WRAS
Spring Stainless steel
TMV2 approved
Piston Udel
Specifications
Flowrate Graph
Maximum hot temperature
85°C
Cold temperature supply range
5-25°C
Maximum static pressure
10bar
Maximum working pressure
5bar
Minimum working pressure
1bar
Factory set temperature
38°C +/-2°C (max 48°C)
Supply pressure differential
5:1
6.0
Pressure (bar)
5.0
4.0
3.0
2.0
1.0
Regulated flow rate
0
(For shower only)
5
8l/min
10
15
20
30
25
35
40
Flow (l/min)
Dimensions (deck mount)
140 - 160
Ø 64
272
100
100
83.5
149
272
56
89
180
200
194
Deck mounted
Wall mounted
Dimensions in mm unless stated otherwise
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9

10. Thermostatic Shower Controls
Heatguard® Bar Shower
The Heatguard® Bar Shower is a TMV2 approved dual control thermostatic bar shower mixer. It is built around a two
cartridge principle, meaning that all the working thermostatic components are included in an easy to replace one-piece
cartridge and the flow control is contained within another cartridge. Check valves and strainers are included within the
design of the shower. A high temperature override button and an economy flow rate override button are included to
allow the user to have total control of the shower, and make adjustments based on their personal preference both for
safety and flow rates. As standard the Heatguard® Bar Shower comes complete with ‘Z’ connectors to install into the
plumbing system, but it can also be installed with an optional wall mounting bracket which can be fixed inside the cavity
wall to give a positive fixing point, water connections and secure centres for the shower to fit onto.
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Rapid failsafe on both hot and cold supply failure
Provides stable mixed water temperature
Includes check valve, strainer and flow regulator
TMV2 and WRAS approved
Additional wall mounting bracket available
Economical flow with user override button
Product Range
THRM 700 060 - Heatguard® Bar Shower
BRKT 700 100 - Wall Mounting Bracket
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11. Thermostatic Shower Controls
Materials
Standards
Body Brass
Complies with BS EN 1111
Seals EPDM
Strainer Stainless steel
Approvals
Cartridge body Udel
WRAS
Spring Stainless steel
TMV2 approved
Piston Udel
Specifications
Maximum hot temperature
85°C
Cold temperature supply range
5-25°C
Maximum static pressure
10bar
Maximum working pressure
5bar
Minimum working pressure
1bar
Factory set temperature
38°C +/-2°C (max 48°C)
Supply pressure differential
5:1
Regulated flow rate
8l/min
Flowrate Graph
6.0
Pressure (bar)
5.0
3.0
2.0
Overide fully open
Economy limit
1.0
Connection size ¾" MBSP - Shower
4.0
½" MBSP - Connector
0
5
10
15
20
25
30
40
35
Flow (l/min)
Dimensions
140 - 160
99
90
Ø 64
100 -120
200
282
92
Dimensions in mm unless stated otherwise
www.rwc.co.uk
11

12. The Safety Valve Specialist
Thermostatic
Shower Controls
Reliance Water Controls Ltd
A Reliance Worldwide Company
Worcester Road, Evesham,
Worcestershire, WR11 4RA, UK
UK - Freephone: 0800 389 5931
Freefax: 0800 389 5932
Outside UK - Tel: +44 (0) 1386 712400
Fax: +44 (0) 1386 712401
Email: sales@rwc.co.uk
www.rwc.co.uk
Reliance has prepared the content of this document
carefully but disclaims all warranties, express or implied,
as to the accuracy of the information contained herein.
Reliance reserves the right to make changes to the
product and the information contained in this document
at any time.
TSHW-001-03/12
© Reliance Water Controls Ltd 2012